Improve tarball URL extraction logic

Refine tarball URL extraction to exclude aarch64 and select the first result.

NonSteamLaunchers.sh

@@ -635,7 +635,11 @@ function download_ge_proton() {
     }
 
     tarball_url=$(curl -s https://api.github.com/repos/GloriousEggroll/proton-ge-custom/releases/latest \
-        | grep browser_download_url | cut -d\" -f4 | grep .tar.gz)
+        | grep browser_download_url \
+        | cut -d\" -f4 \
+        | grep '\.tar\.gz$' \
+        | grep -v 'aarch64' \
+        | head -n1)
 
     if [ -z "$tarball_url" ]; then
         echo "Failed to get tarball URL. Exiting."